Valve for player pianos



Aug. 21, 1928. 1,681,338

A. G. GULBRANSEN VALVE FOR PLAYER PIANOS I Original Filed June s, 1915 @0262 G Gulbmns an Patented Aug. 21, 1928.

uulrsnsrarss ears-air OFFICE.

AXEL e. GULBRANSEN, or CHICAGO, ILLINOIS, AssIeNo It To GULBRANSEN PANY, or CHICAGO, ILLINOIS, A CORPORATIONOF ILLINOIS.

VALVE non PLAYER PIANOS.

Original application filed June 3, 1915, Serial No. 31,815. Patent No. 1,349,273, date'd-Aug'ustlf), 1920.

Divided and this application filed August 9, 1920. Serial No. 402,258.

My invention relates to automatically operated musical instruments and has to do particularly with what are known as player pianos or piano players. It will be obvious thatthe device of my invention maybe applied to organs as well as pianos and, In fact, to anymusical instrument or other device operated in an analogous way. It will be understood that my invention is concerned with what has become known as the action-that'is,the operating means, and need not, therefore, be limited to its application to any particular instrument.

Thepresent invention is divisional of my prior application, Serial No. 31,815, filed June 3, 1915, Patent 1,349,273 August 10, 1920, and is particularly concerned with an improved valve structure for the pneumatic; The primary aim of the invention is to provide an improved simple valve con-l struction for the piano action, whereby the valve is made to move onto and off its seat snugly and evenly, at the same time permltting ample a1r passage around the same.

In order to simplify this description I shall explain my invention and apply it to a player piano, particularly since some of the more limited features are really limited to a player piano and since, in general, the advantages which my invention secures are most pronouncedin its application to such a structure.

As before indicated, my invention has particularly to do with the action, which term has become used in the art to signify' the structure comprising the playing unit and the immediately associated parts. My invention has to do with that class of automatic instruments which is operated pneumatically and therefore these operating units or devices will be seen to be in the form of small bellows commonly known as pneumatics. One of these pneumatics is provided for each note on the piano to be struck and my invention is concerned with the construction of these pneumatics, and particularly the valve mechanism therefor.

The construction of the pneumatic and channel board, as commonly known, will be described generally in the following description,in order that the application of the valve may be clearly understood, but of course, it is to beunderstood also that the application of res ns COM- the valve itself is not the only possible adapt ation of the same, as there are other places in a piano and similar instruments in which such a valve can be employed.

Reference may be had to the following specification and claims and the aceompany' ing drawings, in which:

Figure 1 is an end el-evational view of the. pneumatic action, part being shown in cross section so as-to clearly reveal the interior construction; and I Figure 2 is a detail view of the valve stem arrangement embodying ,the present improvement.

Referringnow to Figure 1 wherein the pneumatic action mechanism is SllOWILit will be seen that the channel board 10 is a single integral member extending from end to end of the casing of the piano and consequently extending entirely across all of the striker rods which, in a piano construction, are disposed behind it, one of the same being indicated at 11. This single integral member 10 is mortised at the rear side of the top throughout the entire length thereof, as illustrated at 12, and a series of. channels arranged longitudinally of the board pass down from this mortised portion to the various pneumatic mechanisms, as will be described, these ch annels being indicated at 13. For each channel 13, a smaller channel 14 is also provided, each channel '14 being preferably in the same transverse plane with its corresponding channel 13. This channel 14 is drilled down from the very top of the board, as illustrated in, Figure 1, and the top of the channel is plugged by means of a member 15. A strip 16 is secured, preferably by means of glue, and other means in addition probably, to the rear face of the board 10 in the mortised portion and a board 17 is secured over this strip and the rear face of the board 10, so as to form the longitudinal channel. 18, which runs seen that the channel 18 is in direct communication with all the passageways 13, which lead downwardly therefrom.

A transverse channel 19 is drilled through the board 17 the strip 16 and part of the board 10 into each of the passageways 14, and a tube, illustrated at 20, extends from each of the channels 19 and is connected to a corresponding opening in the tracker board, not shown. It will be understood that the passing of the note sheet over the tracker board controls the momentary or temporary admission of air to the passageway 19 and the connected parts below.

The actuating pneumatics are arranged in three rows and are staggered in their vertical relation to each other so as to bring each of them in proper registry with the corresponding abstract rod of the piano mechanism. However, the particular arrangement of these pneumatics does not form any part of my present invention and further reference thereto will be unnecessary. i I

The channel and valve shelves or blocks are illustrated at 21, and it will be seen that each of them is secured to the rear face of the channel board 10 by means of relatively long screws 2222, these channel and valve shelves or blocks being preferably also firmly and tightly glued to the face of the channel board 10.

Each of the actuating pneumatics comprises a stationary board 23 and a movable board 24 which is hinged at its forward end to the stationary board 28 by means of a leather hinge 25, the two boards being united to form a collapsible air-tight chamber by means of the bellows cloth 26. The movable board 24 has a rearward extension 27 for engagement with the abutment member 28 carried by the corresponding striker rod 11. It is within the block 21 that the improved valve structure of my invention is located, and I shall describe the same in detail presently.

Each of the boards 23 is firmly secured in proper position to the under side of the proper valve and channel block 21, as clearly illustrated in the drawing. It will be seen thateach of the boards provides a diaphragm chamber 29 which is covered by the diaphragm 30, this chamber 29 being connected with its corresponding passageway 14 by means of the L-shaped passageway 31 in the board 23, the passageway 32 in the block 21 and the passageway 33 in the board 10. The diaphragm 30 is shown in its lowermost position, and it will be understood that the space above it is ample for its movement to the opposite extreme. In axial alignment with the diaphragm 30 the block 21 is provided with an opening 34 and a valve chamber 35. A. valve seat ring 36 is disposed tightly in the top of the opening 37, this ring being preferably of metal so as to form an eilective and durable Valve seat. A head 37 engaged by, and either secured or not secured to the diaphragm 80 is carried by a valve stem 38 which passes upwardly through the opening 34 and through the valve seat ring and at the top is provided with the valve member 40. This valve stem 38 is illustrated in cross section in Figure 2, where it will be seen thatit is effectively guided in the valve seat ring by virtue of its Y-shaped cross section, being composed of the three radial and longitudinal ribs 38, these ribs fairly snugly engaging in the valve seat ring 36 to guide the valve stem and at the same time to permlt of passage of air thereby. It will now beunderstood that when the diaphragm is in its lowermost position, the valve 40 rests upon the valve ring, and when the diaphragm is in its uppermost position the valve 40 is raised so as to make communication between the pets sageway or hole 84 and the valve chamber 35.

A passageway 41 connects the opening 34 with the aperture 42 in the channel board 10, which aperture, in turn, connects with a corresponding passageway or channel 13. The valvechamber 35 communicates with the interior of the corresponding actuating pneumatic by means of two passageways, one of which is shown at 43. The valve chamber 35 is provided with a cover piece 44 which has an opening 45 for the free admission of air. An arch member or dust cap 46 open at the ends passes from end to end of the top channel and valve block 21 and protects all the air inlet openings 45.

As the present invention has to do particularly with the improved valve structure described I shall but briefly describe the operation of the pneumatics, in order that the object of the valve may more clearly be known. It will now be understood that normally the diaphragm 30 is in its lowermost position. This position is assured by gravity and also by the fact that the passageway 14 is bled from the channel 18 through a very restricted aperture 47 in a metal thimble 48 secured in an opening 49 drilled in the board 10 between the passageways 14 and 18. The thimble is inserted through an opening 50 which, after construction, is closed by means of a strip of airtight material indicated. at 51. The passageway 18 is connected. with the power plant by means of a suction tube, not shown, as now well known in the art. It will thus be seen that a constant vacuum is maintained in the passageways 14 and 18 and the connecting passageways, including the diaphragm chamber below the diaphragm 30 so long as air is not admitted through the tracker bar into the corresponding passageway 20. Just as soon as air is admitted through an opening in the note-sheet, it flows throughthe tube 20 and passageways 14, 33, 32, '31 and since a constant vacuum is maintained above the diaphragm by way of the passageways 42, and 41, the diaphragm rises to its uppermost position. This, changes the position of the valve 40. Normally this valve rests upon its seat and the actuating pneumatic is connected directly with the atmosphere through the passageway 43, the valve chamber 35 and the opening 45. When, however,the valve 43 is moved to its uppermost position, it engages the under side of the disc 44 and closes the opening 45. This shuts off the connection to the atmosphere and directly connects the actuating pneumatic with suction. It will be obvious that this collapses the pneumatic and raises the extension 27 so that it will in turn raise the abutment member 28 and consequently the striker rod 11 to sound the corresponding note. When the admission of the atmosphere to the passage 20 has again been cut off by the action of the note sheet, the suction again operates through the aperture 47 to reduce the pressure below the diaphragm 30. This again equalizes the pressure on both sides of the diaphragm and gravity brings down the valve 39 so as to cut off the connection between the suction means and the actuating pneumatic and, instead,

connects the actuating pneumatic with the atr mosphere, so as to permit its extension. An adjusting screw 53 is provided to determine the throw of the movable board of the actuating pneumatic.

As will be clear from the above description, and as clearly illustrated, the valve shelf or block 21 is formed from a single piece of material and the air passages thereof are rectilineal and similarly directed. The passages 32 and 43 may be considered as formed of two portions, an upper main portion inclined downwardly and rearwardly of the block similarly to passage 41, and a shorter vertical portion extending from the under face of the block. It will also be noted that the bore 34 is vertical, and the air passages are disposed in a common vertical plane. All of these features are of importance as the block can be quickly drilled wtih a simple jig, and it is possible to dispose the pneumatics of the respective blocks or shelves closely adjacent effecting a material saving of space, which is always an important consideration in instruments of this character. It is also possible, by my construction, to readily bore out a block or shelf of one continuous piece of wood for reception of the pneumatics in such manner as to eliminate plugged false opening-s and a multiplicity of joints, all of which are possible sources of air leakage. As the shelf or block thus produced is of one piece of wood it can be glued directly to the channel board 10 so as to effect an air tight closure. It will thus be seen that by constructing the valve block or shelf in the manner illustrated and described I materially reduce the cost of production while also very materially increasing the etliciency of the instrument, as compared to instruments in which the valve block or shelf is not ofwood and not formed from a single piece of material.-

I claim i 1. Ina pneumatically actuated musical instrument, a valve block having a bore ext-ending from top to bottom thereof and having its upper" portion enlarged forming a valve chamber, the block being provided with a rectilineal air passage extending from one side of the block and opening into the bore, said block having a second air passage extending from the same side of the block as the first passage, the second passage having an upper rectilineal portion and a lower portion extending from the under face of the block, the block also having a third air passage comprising an upper rectilineal portion extending from the valve chamber and a lower portion extending from the under face of the block.

2. In a pneumatically actuated musical instrun'ient, a valve block having a bore extending from top to bottom thereof and having its upper portion enlarged forming a valve chamber, the block being provided with a ectilineal air passage extending from one side of the block and opening into the bore, said block having a second air passage extendingfrom the same side of the block as the first passage, the second passage having an upper rectilineal portion and a lower portion extending from the under face of the block, the block also having a third air passage comprising an upper rectilineal portion extending from the valve chamber and a lower portion extendin from the under face of the block, the rectilineal portion of each of the second and third air passages being directed similarly to the first air passage.

In a. pneumatically actuated musical instrument, a valve block having a bore extending from top to bottom thereof and enlarged at its upper end forming a valve chamber, said block having two passages extending from one side thereof and disposed in superposed relation, the upper one of said passages being rectilineal and opening into said bore, and the lower passage comprising a rectilineal upper portion and a lower portion extending from the lower face of the block, the block being further provided with a third air passage extending from the valve Clllilb her and including an upper rectilineal portion and a lower portion extending from the lower face of the block.

4. In a pneumatically actuated musical instrument, a valve block having a bore extending from the top to the bottom thereof, and having its upper portion enlarged forming a valve chamber, the block having two air passages extending from one side thereof and disposed in superposed relation, the upper one of the passages being rectilineal and Open ing into said bore, and the lower passage comprising an upper rectilineal portion and a lower portion extending from the under face of the block, the block being further provided with a third air passage extending from the valve chamber and comprising an upper rectilineal portion and a lower portion extending from the under face of the block, the passage opening into the bore and the upper portion of each of the two other passages being all inclined downwardly toward the under face of the block from the side of the block from which the first two air passages extend.

In witness whereof I hereunto subscribe my name this 7th day of August, 1920.

AXEL G. GULBRANSEN. 

